La Sonora makes those little Italian industrial sirens beloved by German factories, but it looks like they make large outdoor ones too. There are also some explosion-proof (antideflagranti) outdoor sirens on the other page. The output frequencies are higher than other European nine-port sirens because they offer them with 11, 10, or 9 "finestre" (windows/ports). I found a similar site in Spain with an identical directional siren. I guess this is either for portable use or in case your town is in the Italian alps and you want your local volunteer siren pointing away from the avalanche slope.
Check out the red vehicle siren on this page. I have never seen one built like this before:
http://www.lasonora.it/Pages/05-sir.html
Lex orandi, lex credendi, lex vivendi.